The role of arbuscular mycorrhizal symbiosis in plant performance under the specific edaphic conditions of serpentine soils

P. Doubková: The role of arbuscular mycorrhizal symbiosis in plant performance under the specific edaphic conditions of serpentine soils Summary Serpentine soils represent a unique environment characterized by unfavourable physicochemical properties involving low calcium to magnesium ratio, increased concentrations of heavy metals, often also deficiencies of essential macronutrients, and low water-holding capacity. Under these adverse conditions, a considerable potential of arbuscular mycorrhizal fungi (AMF) to promote plant growth was hypothesized due to the importance of arbuscular mycorrhizal (AM) symbiosis for plant nutrition and alleviation of various types of abiotic stress. On a model host plant species, Knautia arvensis (Dipsacaceae), we examined: i) occurrence of AM symbiosis and species richness and composition of the native AMF communities; ii) role of AM symbiosis in plant growth, element uptake and drought stress tolerance; iii) edaphic differentiation in plant populations or in AMF symbionts under serpentine vs non-serpentine conditions. Generally, K. arvensis plants showed lower frequency of mycorrhizal root colonization at serpentine compared to the non-serpentine sites. Adjacent serpentine and non-serpentine populations also differed in AMF species assemblages colonizing their roots. Both,...